Mon Apr 17 20:07:32 2023 UTC ()

lua: apply upstream bugfix for "'break' may not properly close variable in a 'for' loop."

Function 'leaveblock' was generating "break" label before removing
variables from the closing block. If 'createlabel' created a 'close'
instruction (which it did when matching a goto/break that exited
the scope of an upvalue), that instruction would use the wrong level.


(nikita)

diff -r1.13 -r1.14 src/external/mit/lua/dist/src/lparser.c

--- src/external/mit/lua/dist/src/lparser.c 2023/04/17 19:17:49	1.13
+++ src/external/mit/lua/dist/src/lparser.c 2023/04/17 20:07:32	1.14

 @@ -1,14 +1,14 @@
-/*	$NetBSD: lparser.c,v 1.13 2023/04/17 19:17:49 nikita Exp $	*/
+/*	$NetBSD: lparser.c,v 1.14 2023/04/17 20:07:32 nikita Exp $	*/
 /*
 ** Id: lparser.c
 ** Lua Parser
 ** See Copyright Notice in lua.h
 */
 #define lparser_c
 #define LUA_CORE
 #include "lprefix.h"
 @@ -668,39 +668,39 @@ static l_noret undefgoto (LexState *ls,
   else {
     msg = "no visible label '%s' for <goto> at line %d";
     msg = luaO_pushfstring(ls->L, msg, getstr(gt->name), gt->line);
+  }
   luaK_semerror(ls, msg);
+}
 static void leaveblock (FuncState *fs) {
   BlockCnt *bl = fs->bl;
   LexState *ls = fs->ls;
   int hasclose = 0;
   int stklevel = reglevel(fs, bl->nactvar);  /* level outside the block */
-  if (bl->isloop)  /* fix pending breaks? */
+  removevars(fs, bl->nactvar);  /* remove block locals */
   lua_assert(bl->nactvar == fs->nactvar);  /* back to level on entry */
   if (bl->isloop)  /* has to fix pending breaks? */
     hasclose = createlabel(ls, luaS_newliteral(ls->L, "break"), 0, 0);
-  if (!hasclose && bl->previous && bl->upval)
+  if (!hasclose && bl->previous && bl->upval)  /* still need a 'close'? */
     luaK_codeABC(fs, OP_CLOSE, stklevel, 0, 0);
   fs->bl = bl->previous;
   removevars(fs, bl->nactvar);
   lua_assert(bl->nactvar == fs->nactvar);
   fs->freereg = stklevel;  /* free registers */
   ls->dyd->label.n = bl->firstlabel;  /* remove local labels */
-  if (bl->previous)  /* inner block? */
+  fs->bl = bl->previous;  /* current block now is previous one */
-    movegotosout(fs, bl);  /* update pending gotos to outer block */
+  if (bl->previous)  /* was it a nested block? */
     movegotosout(fs, bl);  /* update pending gotos to enclosing block */
   else {
-    if (bl->firstgoto < ls->dyd->gt.n)  /* pending gotos in outer block? */
+    if (bl->firstgoto < ls->dyd->gt.n)  /* still pending gotos? */
       undefgoto(ls, &ls->dyd->gt.arr[bl->firstgoto]);  /* error */
+  }
+}
 /*
 ** adds a new prototype into list of prototypes
 */
 static Proto *addprototype (LexState *ls) {
   Proto *clp;
   lua_State *L = ls->L;
   FuncState *fs = ls->fs;
   Proto *f = fs->f;  /* prototype of current function */